On 19 Jan 1997, F. Frank LeFever wrote:
><snip>
> LHS was a hot item 30-35 years ago (e.g. in J. Comp. Physiol. Psychol.)
> but doubt a Medline search (especially if limited to Ovid disk) would
> turn up much--wrong time, wrong journals.
>> I'd welcome the most recent reference and/or the most through OLD
> reference, OR your personal experience as a brain surgeon on rats!
>> I'm especially interested in the exact details of the anorexia and/or
> finickiness of the rats. It was said that they COULD be coaxed to eat
> with a "palatable" diet (and then through graded steps to
> self-sustained eating with a "normal" diet).
>> What EXACTLY is "palatable"? Chocolate has been mentioned, and I
> coaxed one rat along with chocolate covered halvah, but do you know of
> systematic studies on the defining characteristics? (sweetness?
> moistness? other??)
The topic may be old, but it's not dead yet, as indicated by a recent
review by Winn (1995). In my day, we nursed these rats back to survival
using a commercial brand of liquid diet marketed for dieters (chocolate
"Metrecal"), together with chocolate chip cookies. An old story I heard
was to the effect that Teitelbaum first used a brand of egg-nog donated
by a local dairy, but his supply was cut off when he made an offhand
remark at a conference about how terrible the stuff tasted to him. it's
probably not true, but he does mention the use of an evaporated
milk-sugar solution diet in his original report (Teitelbaum and Stellar,
1954).
A later idea was that the LH syndrome paralleled development in
infancy ("reencephalization of function"; see Teitelbaum et al, 1969).
This seems to have resulted in the suggestion that an infant food such as
pablum be used to recover these rats. I believe an explicit suggestion
along these lines was made in print, possibly in a review article by
Edward Stricker, but I haven't been able to find it. Nevertheless, at
least one study (Zigmond and Stricker, 1973) does report the use of
"highly palatable foods, such as Pablum, Metrecal, and sucrose solution".
One final observation is that in the 1970's Richard Keesey initiated an
attack on the classic stages of recovery as described by Teitelbaum and
Epstein. According to Keesey (e.g. see Keesy et al, 1976), the recovery
stages were an artifact or illusory, and using special diets and
tube-feeding merely prolonged the period of inanition. Instead Keesey
argued that the rat would not begin feeding until its weight had dropped
to a new low value which was determined by the extent of brain damage.
Tube-feeding merely slowed the weight-loss until the critical set-point
was reached.
This was an interesting idea. However, I always felt that the evidence
that Keesey provided in support of this claim was open to criticism, and
not as convincing as it might have been. I still don't know whether
tube-feeding and special diets are actually helpful.
References
Keesey, R., et al (1976). Prolonging lateral hypothalmic anorexia bu
tube-feeding. Physiology and Behavior, 17, 367-371.
Teitelbaum, P., & Stellar, E. (1954). Recovery from the failure to eat
produced by hypothalamic lesions. Science, 120, 894--
Zigmond, M., and Srticker, E. (1973). Recovery of feeding and drinking
by rats after intraventricular 6-hydroxydopamine or lateral hypothalamic
lesions. Science, 182, 717-720
Winn, P. (1995). The lateral hypothalamus and motivated behavior: an old
sydrome reassessed and a new perspective gained. Current Directions in
Psychological Science, 4, 182--
Teitelbaum, P. et al (1969). Development of feeding parallels its recovery
after hypothalamic damge. Journal of comparative and physiological
psychology, 67, 430-441
-Stephen
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Stephen Black, Ph.D. tel: (819) 822-9600 ext 2470
Department of Psychology fax: (819) 822-9661
Bishop's University e-mail: sblack at ubishops.ca
Lennoxville, Quebec
J1M 1A9
Canada
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